A brain injury that causes a temporary disturbance in brain function, sometimes with unconsciousness and confusion; traumatic head injuries cause concussions and may result in a headache, along with concentration and memory problems. All traumatic brain injuries are head injuries. When the brain is starved of oxygen for a prolonged period of time, brain damage may occur. Brain damage can occur as a result of a wide range of injuries, illnesses, or conditions. Because of high-risk behaviors, males between ages 15 and 24 are most vulnerable. Neurosurgery, or neurological surgery, is the medical specialty concerned with the prevention, diagnosis, surgical treatment, and rehabilitation of disorders, such as brain injuries which affect any portion of the nervous system including the brain, spinal cord, peripheral nerves, and extra-cranial cerebrovascular system.